Windows 7: Mac OS 10.5.8 - Parallels 7 - Windows 7 - Windows App Won't Install

I have an iMac running 10.5.8. I installed and activated the Parallels 7 trial (plus Parallel Tools) after seeing that it would work on my Mac. Then I installed Windows 7 Pro. Everything was working perfectly until I tried to install Practice Partner 9.3.1, a Windows app from Elsevier (a tech at the company confirmed that the app runs under Windows 7). I can see all the files on the app's installation disk from my Mac Desktop. But when I start Parallels / Windows, the app installation CD completely disappears from the Mac Desktop. Or if I already have Windows 7 running and insert the installation CD for the app, the CD never appears on the Mac Desktop.

I was told to make a new folder on the Windows Desktop, which I did, and copy the setup.exe file to that folder from the app's installation CD using drag-and-drop. Can't do that when I can't see the installation CD.

In Windows 7, when I click on Computer and look at the drives, I see the installation CD; when I click on that, the turquoise circle spins forever and nothing happens.

Any idea how I can get this app installed?! Thanks in advance for any help!

Lynda